Cardiac function in rats selectively bred for low- and high-capacity running
Cardiac function in rats selectively bred for low- and high-capacity running
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DOI：
10.1152/ajpregu.2001.281.6.r1787
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发表时间：
2001-12-01
影响因子：
2.8
通讯作者：
Britton, SL
中科院分区：
文献类型：
--
作者：
Hussain, SO;Barbato, JC;Britton, SL
大鼠遗传模型的内在（即未经训练的）低能力跑者（LCR）和高能力跑者（HCR）正在通过人工选择育种为跑步机发展。在第3代时，这些线路的运行容量相差114%。我们使用第3代大鼠来验证HCR相对于LCR具有1)更大的离体心脏表现和2)更强的心肌缺血损伤抵抗力的假设。衰竭时LCR跑227 +/- 7 m， HCR跑994 +/- 11 m（差异337%，P < 0.001）。使用Langendorff-Neely工作心脏准备剂，通过恒定负荷前（15 mmHg）和负荷后（70 mmHg）产生的心输出量（CO）评估离体心脏性能。CO平均为33.5±2.0 ml.min（-1）。LCR心脏g(-1) 49.9 +/- 1.4 ml.min（-1）。HCR心脏g(-1)（差异49%，P < 0.001）。全脑缺血25分钟后，各组血氧恢复无明显差异。这些结果表明，1)心脏性能的提高是两种线路运行能力差异的部分原因；2)与运动训练不同，基因决定的内在运动能力不会影响25分钟全心低流量缺血后的恢复。
Rat genetic models of intrinsic (i.e., untrained) low-capacity runners (LCR) and high-capacity runners (HCR) are being developed by artificial selective breeding for treadmill running. At generation 3, these lines differed in running capacity by 114%. We used generation 3 rats to test the hypotheses that HCR, relative to LCR, have 1) greater isolated cardiac performance and 2) more resistance to myocardial ischemic insult. The LCR ran for 227 +/- 7 m, and the HCR ran 994 +/- 11 m at exhaustion (337% difference, P < 0.001). Isolated heart performance was assessed from cardiac output (CO) generated at constant preload (15 mmHg) and afterload (70 mmHg) using a Langendorff-Neely working heart preparation. CO averaged 33.5 +/- 2.0 ml.min(-1).g(-1) in LCR hearts and 49.9 +/- 1.4 ml.min(-1).g(-1) in HCR hearts (49% difference, P < 0.001). Recovery of CO after 25 min of global ischemia was not different between the lines. These results suggest that 1) increased cardiac performance accounts for part of the difference in running capacity between the lines; and 2) unlike exercise training, genetically determined intrinsic capacity for exercise does not influence the recovery from 25 min of global low-flow cardiac ischemia.